Traditionally, the circuit breaker is designed to be the weak link in a home or commercial electrical system and designed to fail safely. In the event a circuit draws more current than it is designed to handle, the corresponding wiring gets hot and problems can occur including fires. The use of so-called “overcurrent” safety devices such as the circuit breaker are designed to prevent such fires by breaking the circuit and stopping the occurrence of heat build due to a greater than expected level of electrical current. Circuit breakers connect to the hot bus bars and come in a variety of types and capacities.
Single Pole Breakers provide 120 volts and typically come in ratings of 15 to 20 amps. These breakers make up the majority of breakers in a standard home. Double Pole Breakers provide 240 volts and typically come in ratings from 15 to 50 amps. These breakers generally serve dedicated circuits for large appliances such as electric dryers, stoves and air conditioners.
The service main panel is typically configured with two bus bars (L1, L2 and a ground neutral bar) typically comprised of a thick strip of copper or aluminum that conducts electricity within a distribution board, switchboard, substation or any other electrical apparatus. Bus bars are typically used to carry or dispense very large currents to several devices that are inside the switchgear such as to home appliances or other electricity consuming apparatus.
Modernly, remodeling and installation of alternative energy devices including solar panels, wind turbines or other power generating equipment in a home or commercial building have required either replacing the structure's electrical main panel or installation of a sub panel in order to accommodate the extra load generated by the additional alternative energy devices being installed. Replacement of a new service panel and/or installation of new sub panels to an existing electrical system results in significant expenses to the home or building owner committing the owner to an investment of several years of alternative energy generation to recoup the expense associated with installation of the alternative energy device.
National Electrical Code (NEC) sections 690.64(B)/705.12(D) govern the requirements and limitations of bus bar load. Bus bars are generally intended to deliver electrical power from the main panel to the various circuit breakers that are employed in distribution of power to a residential or commercial dwelling. 705.12(D)(2) provides in part: Buss or Conductor Rating: The Sum of the ampere ratings of overcurrent devices in circuits supplying power to a bus bar or conductor shall not exceed 120 percent of the rating of the bus bar or conductor.
From a practical perspective, regulations that govern electrical power through a bus bar preclude the transfer of such power beyond 120% of the amperage rating of the bus bar. Accordingly, to maintain compliance with regulations, the installation of alternative energy sources to a home or commercial building including solar power, wind turbines and the like, require a complete replacement of the existing main panel, or addition of a sub panel to accommodate excess power back fed to the utility since excess power can potentially overload the amperage rating of the bus bars leading to the risk of fire.
Various devices have sought to address issues in detecting and preventing instances of overcurrent as well as in managing back fed power generated from alternative energy sources to the power grid, however none have fully addressed shortcomings currently existing in the art. For example, U.S. Patent Application number 2012/0300348 describes a circuit breaker and trip logic that includes fault detection within each of a plurality of circuit breakers whereby the trip logic enables tripping options to be selected for each of the circuit breakers. The disclosure however, does not provide a solution relating to the matter of excess power management through bus bars of a specific amperage. More importantly, it fails to address avoiding the necessity of replacement an existing main panel which results in significant time and expense to a home owner or commercial building owner.
U.S. Pat. No. 4,288,78 to Arnhold et al., describes a circuit breaker for interrupting a current circuit in response to an overload current, or a short circuit current, or in response to an earth leakage or fault current. It further describes one or several single pole circuit breakers with an earth leakage current circuit breaker for such overcurrents. It however, does not disclose or suggest a provision for the management of overcurrent through bus bars generated from alternative energy sources such as for example, newly installed solar panels or wind turbine assemblies.
U.S. Pat. No. 4,100,587 describes a circuit configured between a power supply and a load for detecting the flow of excess power from a load back through the supply. The circuit is described as sensing the current flowing between the power supply and the load, and also senses the output voltage from the power supply with further embodiments that act to generate a signal to disconnect the power supply from the load when the average power signal is above a certain threshold. Again, the device and methods fail to address the issue of significant time and expense in installation of alternative energy sources and for avoiding the significant costs and time required in maintaining current within NEC specifications even during instances of overcurrent generated from such alternative energy sources.
Accordingly, difficulties in the field of electrical back feed to the power grid and cost savings associated with the installation of alternative energy sources remain. Existing solutions fail to address particular deficiencies that confront businesses and consumers seeking alternatives to the existing art and a solution to advancing cost and time saving measures for greater implementation of alternative energy options remains elusive. The present invention seeks to address these shortcomings.